Temporal analysis of land use and transportation investments with geographic information system

Land use and transportation interaction has been a research topic for several decades. There have been efforts to identify impacts of transportation on land use from several different perspectives. One focus has been the role of transportation improvements in encouraging new land developments or relocation of activities due to improved accessibility. The impacts studied have included property values and increased development. Another focus has been on the changes in travel behavior due to better mobility and accessibility. Most studies to date have been conducted in metropolitan level, thus unable to account for interactions spatially and temporally at smaller geographic scales. ^ In this study, a framework for studying the temporal interactions between transportation and land use was proposed and applied to three selected corridor areas in Miami-Dade County, Florida. The framework consists of two parts: one is developing of temporal data and the other is applying time series analysis to this temporal data to identify their dynamic interactions. Temporal GIS databases were constructed and used to compile building permit data and transportation improvement projects. Two types of time series analysis approaches were utilized: univariate models and multivariate models. Time series analysis is designed to describe the dynamic consequences of time series by developing models and forecasting the future of the system based on historical trends. Model estimation results from the selected corridors were then compared. ^ It was found that the time series models predicted residential development better than commercial development. It was also found that results from three study corridors varied in terms of the magnitude of impacts, length of lags, significance of the variables, and the model structure. Long-run effect or cumulated impact of transportation improvement on land developments was also measured with time series techniques. The study offered evidence that congestion negatively impacted development and transportation investments encouraged land development. ^

Algorithms for scheduling parallel batch processing machines with non-identical job ready times

This research is motivated by a practical application observed at a printed circuit board (PCB) manufacturing facility. After assembly, the PCBs (or jobs) are tested in environmental stress screening (ESS) chambers (or batch processing machines) to detect early failures. Several PCBs can be simultaneously tested as long as the total size of all the PCBs in the batch does not violate the chamber capacity. PCBs from different production lines arrive dynamically to a queue in front of a set of identical ESS chambers, where they are grouped into batches for testing. Each line delivers PCBs that vary in size and require different testing (or processing) times. Once a batch is formed, its processing time is the longest processing time among the PCBs in the batch, and its ready time is given by the PCB arriving last to the batch. ESS chambers are expensive and a bottleneck. Consequently, its makespan has to be minimized. ^ A mixed-integer formulation is proposed for the problem under study and compared to a formulation recently published. The proposed formulation is better in terms of the number of decision variables, linear constraints and run time. A procedure to compute the lower bound is proposed. For sparse problems (i.e. when job ready times are dispersed widely), the lower bounds are close to optimum. ^ The problem under study is NP-hard. Consequently, five heuristics, two metaheuristics (i.e. simulated annealing (SA) and greedy randomized adaptive search procedure (GRASP)), and a decomposition approach (i.e. column generation) are proposed—especially to solve problem instances which require prohibitively long run times when a commercial solver is used. Extensive experimental study was conducted to evaluate the different solution approaches based on the solution quality and run time. ^ The decomposition approach improved the lower bounds (or linear relaxation solution) of the mixed-integer formulation. At least one of the proposed heuristic outperforms the Modified Delay heuristic from the literature. For sparse problems, almost all the heuristics report a solution close to optimum. GRASP outperforms SA at a higher computational cost. The proposed approaches are viable to implement as the run time is very short. ^

Three essays on asset pricing

In this dissertation, I investigate three related topics on asset pricing: the consumption-based asset pricing under long-run risks and fat tails, the pricing of VIX (CBOE Volatility Index) options and the market price of risk embedded in stock returns and stock options. These three topics are fully explored in Chapter II through IV. Chapter V summarizes the main conclusions. In Chapter II, I explore the effects of fat tails on the equilibrium implications of the long run risks model of asset pricing by introducing innovations with dampened power law to consumption and dividends growth processes. I estimate the structural parameters of the proposed model by maximum likelihood. I find that the stochastic volatility model with fat tails can, without resorting to high risk aversion, generate implied risk premium, expected risk free rate and their volatilities comparable to the magnitudes observed in data. In Chapter III, I examine the pricing performance of VIX option models. The contention that simpler-is-better is supported by the empirical evidence using actual VIX option market data. I find that no model has small pricing errors over the entire range of strike prices and times to expiration. In general, Whaley’s Black-like option model produces the best overall results, supporting the simpler-is-better contention. However, the Whaley model does under/overprice out-of-the-money call/put VIX options, which is contrary to the behavior of stock index option pricing models. In Chapter IV, I explore risk pricing through a model of time-changed Lvy processes based on the joint evidence from individual stock options and underlying stocks. I specify a pricing kernel that prices idiosyncratic and systematic risks. This approach to examining risk premia on stocks deviates from existing studies. The empirical results show that the market pays positive premia for idiosyncratic and market jump-diffusion risk, and idiosyncratic volatility risk. However, there is no consensus on the premium for market volatility risk. It can be positive or negative. The positive premium on idiosyncratic risk runs contrary to the implications of traditional capital asset pricing theory.

Three essays on labor liberalization and its effects on world economy

This dissertation consists of three theoretical essays on immigration, international trade and political economy. The first two essays analyze the political economy of immigration in developed countries. The third essay explores new ground on the effects of labor liberalization in developing countries. Trade economists have witnessed remarkable methodological developments in mathematical and game theoretical models during the last seventy years. This dissertation benefits from these advances to analyze economic issues related to immigration. The first essay applies a long run general equilibrium trade model similar to Krugman (1980), and blends it with the median voter ala-Mayer (1984) framework. The second essay uses a short run general equilibrium specific factor trade model similar to Jones (1975) and incorporates it with the median voter model similar to Benhabib (1997). The third essay employs a five stage game theoretical approach similar to Vogel (2007) and solves it by the method of backward induction. The first essay shows that labor liberalization is more likely to come about in societies that have more taste for varieties, and that workers and capital owners could share the same positive stance toward labor liberalization. In a dynamic model, it demonstrates that the median voter is willing to accept fewer immigrants in the first period in order to preserve her domestic political influence in the second period threatened by the naturalization of these immigrants. The second essay shows that the liberalization of labor depends on the host country's stock and distribution of capital, and the number of groups of skilled workers within each country. I demonstrate that the more types of goods both countries produce, the more liberal the host country is toward immigration. The third essay proposes a theory of free movement of goods and labor between two economies with imperfect labor contracts. The heart of my analysis lies in the determinants of talent development where individuals' decisions to emigrate are related to the fixed costs of emigration. Finally, free trade and labor affect income via an indirect effect on individuals' incentives to invest in the skill levels and a direct effect on the prices of goods.

Three essays on entrepreneurial motivation, entry, exit and monetary rewards

This dissertation analyzes rewards and motivations of self-employment. In light of recent research contributions of Barton Hamilton (2000), which find entrepreneurship not as financially rewarding as wage work, my dissertation attempts to both verify and explain this claim. The first essay proposes a theoretical model of evolution of erroneous earnings expectations on part of a nascent entrepreneur. Inability to observe, survey, and take into account all of the returns to entrepreneurship prior to business entry creates a biased set of beliefs on part of the potential entrants. Using Bayesian learning, a nascent entrepreneur starting out with correct perception of profit distribution arrives at erroneous beliefs by incorporating limited information collected from existing businesses. An observed distribution of surviving businesses would exhibit higher earnings because of previous, unobserved, business failure entrepreneur get an overly positive view of her profit potential. Hence, the chapter offers a unique method of modeling overconfidence. The second essay undertakes dynamic empirical comparison of earnings received by business owners and their wage counterparts. Using Survey of Income and Program Participation (SIPP) I examine both short and long run returns to entrepreneurship comparing theses rewards to wage earners returns. I pay particular attention to transitions into and out of business ownership. I estimate entire earnings distribution. To characterize dynamic aspect of changes to individuals’ earnings I split the income distribution into five income quintiles and follow survey participants over the period of seven years. I find that period-to-period transitions to be Markovian. I find business tenure to be short, business ownership is costly in the short and rewarding in the long run. The third essay considered different reporting schemes applied to the self-employed. It is another empirical investigation of entrepreneurial earning uses Panel Study of Income Dynamics (PSID). I find entrepreneurs while reporting lower than wage workers earnings enjoy significant consumption premiums. I observe evidence of income underreporting by entrepreneurs. This finding suggests a need for better earning comparison metrics and proposes to use consumption rather than income metrics for future comparisons.

Carbon nanotube based systems for high energy efficient applications

In the current age of fast-depleting conventional energy sources, top priority is given to exploring non-conventional energy sources, designing highly efficient energy storage systems and converting existing machines/instruments/devices into energy-efficient ones. ‘Energy efficiency’ is one of the important challenges for today’s scientific and research community, worldwide. In line with this demand, the current research was focused on developing two highly energy-efficient devices – field emitters and Li-ion batteries, using beneficial properties of carbon nanotubes (CNT). Interface-engineered, directly grown CNTs were used as cathode in field emitters, while similar structure was applied as anode in Li-ion batteries. Interface engineering was found to offer minimum resistance to electron flow and strong bonding with the substrate. Both field emitters and Li-ion battery anodes were benefitted from these advantages, demonstrating high energy efficiency. Field emitter, developed during this research, could be characterized by low turn-on field, high emission current, very high field enhancement factor and extremely good stability during long-run. Further, application of 3-dimensional design to these field emitters resulted in achieving one of the highest emission current densities reported so far. The 3-D field emitter registered 27 times increase in current density, as compared to their 2-D counterparts. These achievements were further followed by adding new functionalities, transparency and flexibility, to field emitters, keeping in view of current demand for flexible displays. A CNT-graphene hybrid structure showed appreciable emission, along with very good transparency and flexibility. Li-ion battery anodes, prepared using the interface-engineered CNTs, have offered 140% increment in capacity, as compared to conventional graphite anodes. Further, it has shown very good rate capability and an exceptional ‘zero capacity degradation’ during long cycle operation. Enhanced safety and charge transfer mechanism of this novel anode structure could be explained from structural characterization. In an attempt to progress further, CNTs were coated with ultrathin alumina by atomic layer deposition technique. These alumina-coated CNT anodes offered much higher capacity and an exceptional rate capability, with very low capacity degradation in higher current densities. These highly energy efficient CNT based anodes are expected to enhance capacities of future Li-ion batteries.

Indirect Cost Factors In Menu Pricing

In the discussion - Indirect Cost Factors in Menu Pricing – by David V. Pavesic, Associate Professor, Hotel, Restaurant and Travel Administration at Georgia State University, Associate Professor Pavesic initially states: “Rational pricing methodologies have traditionally employed quantitative factors to mark up food and beverage or food and labor because these costs can be isolated and allocated to specific menu items. There are, however, a number of indirect costs that can influence the price charged because they provide added value to the customer or are affected by supply/demand factors. The author discusses these costs and factors that must be taken into account in pricing decisions. Professor Pavesic offers as a given that menu pricing should cover costs, return a profit, reflect a value for the customer, and in the long run, attract customers and market the establishment. “Prices that are too high will drive customers away, and prices that are too low will sacrifice profit,” Professor Pavesic puts it succinctly. To dovetail with this premise the author provides that although food costs measure markedly into menu pricing, other factors such as equipment utilization, popularity/demand, and marketing are but a few of the parenthetic factors also to be considered. “… there is no single method that can be used to mark up every item on any given restaurant menu. One must employ a combination of methodologies and theories,” says Professor Pavesic. “Therefore, when properly carried out, prices will reflect food cost percentages, individual and/or weighted contribution margins, price points, and desired check averages, as well as factors driven by intuition, competition, and demand.” Additionally, Professor Pavesic wants you to know that value, as opposed to maximizing revenue, should be a primary motivating factor when designing menu pricing. This philosophy does come with certain caveats, and he explains them to you. Generically speaking, Professor Pavesic says, “The market ultimately determines the price one can charge.” But, in fine-tuning that decree he further offers, “Lower prices do not automatically translate into value and bargain in the minds of the customers. Having the lowest prices in your market may not bring customers or profit. “Too often operators engage in price wars through discount promotions and find that profits fall and their image in the marketplace is lowered,” Professor Pavesic warns. In reference to intangibles that influence menu pricing, service is at the top of the list. Ambience, location, amenities, product [i.e. food] presentation, and price elasticity are discussed as well. Be aware of price-value perception; Professor Pavesic explains this concept to you. Professor Pavesic closes with a brief overview of a la carte pricing; its pros and cons.

The adoption of retail electronic commerce: an empirical investigation

The purpose of this study was to empirically investigate the adoption of retail electronic commerce (REC). REC is a business transaction which takes place over the Internet between a casual consumer and a firm. The consumer has no long-term relationship with the firm, orders a good or service, and pays with a credit card. To date, most REC applications have not been profitable. To build profitable REC applications a better understanding of the system's users is required. The research model hypothesizes that the level of REC buying is dependent upon the Buying Characteristics of Internet Use and Search Experience plus the Channel Characteristics of Beliefs About Internet Vendors and Beliefs About Internet Security. The effect of these factors is modified by Time. Additional research questions ask about the different types of REC buyers, the differences between these groups, and how these groups evolved over time. To answer these research questions I analyzed publically available data collected over a three-year period by the Georgia Institute of Technology Graphics and Visualization Unit over the Internet. Findings indicate the model best predicts Number of Purchases in a future period, and that Buyer Characteristics are most important to this determination. Further, this model is evolving over Time making Buyer Characteristics predict Number of Purchases better in more recent survey administrations. Buyers clustered into five groups based on level of buying and move through various levels and buy increasing Number of Purchases over time. This is the first large scale research project to investigate the evolution of REC. This implications are significant. Practitioners with casual consumer customers need to deploy a finely tuned REC strategy, understand their buyers, capitalize on the company reputation on the Internet, install an Internet-compatible infrastructure, and web-enable order-entry/inventory/fulfillment/ shipping applications. Researchers might wish to expand on the Buyer Characteristics of the model and/or explore alternative dependent variables. Further, alternative theories such as Population Ecology or Transaction Cost Economics might further illuminate this new I.S. research domain.

Recruiting and developing technicians for hotel food service operations

The thesis which follows is a study of recruiting and developing skilled workers for Hotel Food Service Operations in the Miami area. The aim of the study is to bring to the attention of personnel management the role of recruiting and training in providing the skilled people needed for their operation in the short and long run as well. The study was done as a case study of the medium and large size hotels which have a minimum of 250 units each in the Miami area. However, the study has been generalized where it is possible, and when data permitted. The primary data was collected by the use of the questionnaire survey method composed of key questions about recruiting, training and sources of skilled people, turnover reasons, etc. Eight tables have been constructed, analyzed and interpreted. A personal opinion was mentioned in the interpretation of each table's data. It was found that personnel management should provide a better recruiting and developing procedures in order to attract more qualified people, particularly among the youngsters who are potential skilled workers for the future. It was concluded that the quality of work life, the benefits, and the opportunities for advancement in the food and beverage operations play a significant role in an employee's decision to stay with a particular job, and to acquire the necessary skills.

Three Essays on Asset Pricing

In this dissertation, I investigate three related topics on asset pricing: the consumption-based asset pricing under long-run risks and fat tails, the pricing of VIX (CBOE Volatility Index) options and the market price of risk embedded in stock returns and stock options. These three topics are fully explored in Chapter II through IV. Chapter V summarizes the main conclusions. In Chapter II, I explore the effects of fat tails on the equilibrium implications of the long run risks model of asset pricing by introducing innovations with dampened power law to consumption and dividends growth processes. I estimate the structural parameters of the proposed model by maximum likelihood. I find that the stochastic volatility model with fat tails can, without resorting to high risk aversion, generate implied risk premium, expected risk free rate and their volatilities comparable to the magnitudes observed in data. In Chapter III, I examine the pricing performance of VIX option models. The contention that simpler-is-better is supported by the empirical evidence using actual VIX option market data. I find that no model has small pricing errors over the entire range of strike prices and times to expiration. In general, Whaley’s Black-like option model produces the best overall results, supporting the simpler-is-better contention. However, the Whaley model does under/overprice out-of-the-money call/put VIX options, which is contrary to the behavior of stock index option pricing models. In Chapter IV, I explore risk pricing through a model of time-changed Lévy processes based on the joint evidence from individual stock options and underlying stocks. I specify a pricing kernel that prices idiosyncratic and systematic risks. This approach to examining risk premia on stocks deviates from existing studies. The empirical results show that the market pays positive premia for idiosyncratic and market jump-diffusion risk, and idiosyncratic volatility risk. However, there is no consensus on the premium for market volatility risk. It can be positive or negative. The positive premium on idiosyncratic risk runs contrary to the implications of traditional capital asset pricing theory.

Half-degree gridded nitrogen and phosphorus fertilizer use for global agriculture production during 1900-2013

In addition to enhance agricultural productivity, synthetic nitrogen (N) and phosphorous (P) fertilizer application in croplands dramatically altered global nutrient budget, water quality, greenhouse gas balance, and their feedbacks to the climate system. However, due to the lack of geospatial fertilizer input data, current Earth system/land surface modeling studies have to ignore or use over-simplified data (e.g., static, spatially uniform fertilizer use) to characterize agricultural N and P input over decadal or century-long period. We therefore develop a global time-series gridded data of annual synthetic N and P fertilizer use rate in croplands, matched with HYDE 3,2 historical land use maps, at a resolution of 0.5º latitude by longitude during 1900-2013. Our data indicate N and P fertilizer use rates increased by approximately 8 times and 3 times, respectively, since the year 1961, when IFA (International Fertilizer Industry Association) and FAO (Food and Agricultural Organization) survey of country-level fertilizer input were available. Considering cropland expansion, increase of total fertilizer consumption amount is even larger. Hotspots of agricultural N fertilizer use shifted from the U.S. and Western Europe in the 1960s to East Asia in the early 21st century. P fertilizer input show the similar pattern with additional hotspot in Brazil. We find a global increase of fertilizer N/P ratio by 0.8 g N/g P per decade (p< 0.05) during 1961-2013, which may have important global implication of human impacts on agroecosystem functions in the long run. Our data can serve as one of critical input drivers for regional and global assessment on agricultural productivity, crop yield, agriculture-derived greenhouse gas balance, global nutrient budget, land-to-aquatic nutrient loss, and ecosystem feedback to the climate system.

Termos de troca, preço das commodities e o crescimento brasileiro : uma análise sob o prisma da restrição externa

This study aims to investigate the relationship between terms of trade and the long-term growth of Brazilian economy, from the perspective of external constraint, between the period 1994 to 2014. For this purpose, it is based on Thirlwall's (1979) original contribution, in order to empirically test the terms of trade contribution for determining the Brazilian growth potential product equivalent with Balance of Payments equilibriun. Using cointegration method, which seeks to analyze the long-term relationship between the variables, and subdividing the period into two sub-periods, 1994-2004 and 2004-2014, we estimate and compare real and hypothetical income elasticities and predicted and observed growth rates, with and without the terms of trade, for each period. The obteined results show that the inclusion of terms of trade in the empirical procedure to test the validity of Thirlwall's Law lead to higher growth rates obtained by the model (hypothetical), for the entire period 1994-2014 and for the sub-period 2004 -2014. This "theoretical" relaxation of the external constraint, caused by the inclusion of the terms of trade in traditional Thirlwall's rule, overestimated the average real growth rate for these periods, while the traditional Thirlwall's Law - without terms of trade - has adapted better to the real behavior of Brazilian economy. Thus, despite having contributed potentially for the relaxation of external constraint on Brazilian growth, the effect of terms of trade may have been offset by the negative performance of other Balance of Payments components, as capital flows and interest, profits and dividends payments abroad.

Debt-growth linkages in EMU across countries and time horizons

This paper contributes to the literature by empirically examining whether the influence of public debt on economic growth differs between the short and the long run and presents different patterns across euro-area countries. To this end, we use annual data from both central and peripheral countries of the European Economic and Monetary Union (EMU) for the 1960-2012 period and estimate a growth model augmented for public debt using the Autoregressive Distributed Lag (ARDL) bounds testing approach. Our findings tend to support the view that public debt always has a negative impact on the long-run performance of EMU countries, whilst its short-run effect may be positive depending on the country.

Sexual risk behaviors and HIV risk among Americans aged 50 years or older: a review.

Although HIV-related sexual risk behaviors have been studied extensively in adolescents and young adults, there is limited information about these behaviors among older Americans, which make up a growing segment of the US population and an understudied population. This review of the literature dealing with sexual behaviors that increase the risk of becoming HIV-infected found a low prevalence of condom use among older adults, even when not in a long-term relationship with a single partner. A seminal study by Schick et al published in 2010 reported that the prevalence of condom use at last intercourse was highest among those aged 50-59 years (24.3%; 95% confidence interval, 15.6-35.8) and declined with age, with a 17.1% prevalence among those aged 60-69 years (17.1%; 95% confidence interval, 7.3-34.2). Studies have shown that older Americans may underestimate their risk of becoming HIV-infected. Substance use also increases the risk for sexual risk behaviors, and studies have indicated that the prevalence of substance use among older adults has increased in the past decade. As is the case with younger adults, the prevalence of HIV infections is elevated among ethnic minorities, drug users (eg, injection drug users), and men who have sex with men. When infected, older adults are likely to be diagnosed with HIV-related medical disorders later in the course of illness compared with their younger counterparts. Physicians are less likely to discuss sexual risk behaviors with older adults and to test them for HIV compared with younger adults. Thus, it is important to educate clinicians about sexual risk behaviors in the older age group and to design preventive interventions specifically designed for older adults.

Making Good Citizens: Policy Approaches to Increasing Civic Participation

In this dissertation, I explore the impact of several public policies on civic participation. Using a unique combination of school administrative and public–use voter files and methods for causal inference, I evaluate the impact of three new, as of yet unexplored, policies: one informational, one institutional, and one skill–based. Chapter 2 examines the causal effect of No Child Left Behind’s performance-based accountability school failure signals on turnout in school board elections and on individuals’ use of exit. I find that failure signals mobilize citizens both at the ballot box and by encouraging them to vote with their feet. However, these increases in voice and exit come primarily from citizens who already active—thus exacerbating inequalities in both forms of participation. Chapter 3 examines the causal effect of preregistration—an electoral reform that allows young citizens to enroll in the electoral system before turning 18, while also providing them with various in-school supports. Using data from the Current Population Survey and Florida Voter Files and multiple methods for causal inference, I (with my coauthor listed below) show that preregistration mobilizes and does so for a diverse set of citizens. Finally, Chapter 4 examines the impact of psychosocial or so called non-cognitive skills on voter turnout. Using information from the Fast Track intervention, I show that early– childhood investments in psychosocial skills have large, long-run spillovers on civic participation. These gains are widely distributed, being especially large for those least likely to participate. These chapters provide clear insights that reach across disciplinary boundaries and speak to current policy debates. In placing specific attention not only on whether these programs mobilize, but also on who they mobilize, I provide scholars and practitioners with new ways of thinking about how to address stubbornly low and unequal rates of citizen engagement.